Handle "untitled" files in Neovim

[dhruvmanila]

Currently, the language server crashes with the following panic:

   0.000076625s  INFO main ruff_server::server: No workspace settings found for file:///Users/dhruv/playground/ruff, using default settings
   0.016819875s DEBUG ThreadId(15) ruff_server::session::index::ruff_settings: Ignored path via `exclude`: /Users/dhruv/playground/ruff/.vscode
   0.025011584s  INFO main ruff_server::session::index: Registering workspace: /Users/dhruv/playground/ruff
   0.025738917s TRACE ruff:main notification{method="textDocument/didOpen"}: ruff_server::server::api: enter
   0.026116917s TRACE ruff:worker:0 request{id=2 method="textDocument/diagnostic"}: ruff_server::server::api: enter
   0.026236834s DEBUG ruff:worker:0 request{id=2 method="textDocument/diagnostic"}: ruff_server::resolve: Included path via `include`: /Users/dhruv/playground/ruff/type_inference/definition_vs_declaration.py
   0.027171209s  INFO     ruff:main ruff_server::server: Configuration file watcher successfully registered
  24.044284625s TRACE     ruff:main notification{method="workspace/didChangeWorkspaceFolders"}: ruff_server::server::api: enter
  24.044426375s ERROR     ruff:main notification{method="workspace/didChangeWorkspaceFolders"}: ruff_server::server::api: An error occurred while running workspace/didChangeWorkspaceFolders: Failed to convert workspace URL to file path: file://./
  24.044570667s TRACE     ruff:main notification{method="textDocument/didOpen"}: ruff_server::server::api: enter
  24.100126375s  WARN     ruff:main ruff_server::session::index: No settings available for file:/// - falling back to default settings
  24.101414459s TRACE ruff:worker:2 request{id=3 method="textDocument/diagnostic"}: ruff_server::server::api: enter
  24.101510542s DEBUG ruff:worker:2 request{id=3 method="textDocument/diagnostic"}: ruff_server::resolve: Included path via Python language ID: /
  24.101617792s ERROR ruff:worker:2 request{id=3 method="textDocument/diagnostic"}: ruff_server::server: panicked at crates/ruff_server/src/lint.rs:89:18:
a path to a document should have a parent path

At 24.044284625s, the unnamed buffer has been assigned the filetype as Python in Neovim which triggers the following notifications from the client to the server:

didChangeWorkspaceFolders:

[DEBUG][2025-01-10 13:32:36] .../vim/lsp/rpc.lua:286	"rpc.send"	{
  jsonrpc = "2.0",
  method = "workspace/didChangeWorkspaceFolders",
  params = {
    event = {
      added = { {
          name = ".",
          uri = "file://."
        } },
      removed = {}
    }
  }
}

which fails with the following error:

  24.044426375s ERROR     ruff:main notification{method="workspace/didChangeWorkspaceFolders"}: ruff_server::server::api: An error occurred while running workspace/didChangeWorkspaceFolders: Failed to convert workspace URL to file path: file://./

textDocument/didOpen:

[DEBUG][2025-01-10 13:32:36] .../vim/lsp/rpc.lua:286	"rpc.send"	{
  jsonrpc = "2.0",
  method = "textDocument/didOpen",
  params = {
    textDocument = {
      languageId = "python",
      text = "\n",
      uri = "file://",
      version = 0
    }
  }
}

textDocument/diagnostic:

[DEBUG][2025-01-10 13:32:36] .../vim/lsp/rpc.lua:286	"rpc.send"	{
  id = 2,
  jsonrpc = "2.0",
  method = "textDocument/diagnostic",
  params = {
    range = {
      ["end"] = {
        character = 0,
        line = 1
      },
      start = {
        character = 0,
        line = 0
      }
    },
    textDocument = {
      uri = "file://"
    }
  }
}

[MichaReiser]

Hmm this is interesting. Can you open multiple unnamed buffers? Do they get unique uris? Is this even a valid file path?

[dhruvmanila]

Yes, you can open multiple unnamed buffers. They are using the same URIs.

[MichaReiser]

Yes, you can open multiple unnamed buffers. They are using the same URIs.

That at least seems a bug to me in neovim because the server can now no longer distinguish between them. I think neovim should not use file::// for unnamed buffers but do the same as VS code and use some other non-file path

[MichaReiser]

See #12336

[dhruvmanila]

Yeah, I saw the Neovim issue (neovim/neovim#21276) but that seems to have concluded with continue using "file://" until using "untitled://" is actually the recommended way in the protocol.

[dhruvmanila]

So, this was merged neovim/neovim#22407 but was quickly reverted neovim/neovim#22604

[dhruvmanila]

Could this be a bug in the URI parsing library? The vscode-uri library is able to parse file://./:

l {
  scheme: 'file',
  authority: '.',
  path: '/',
  query: '',
  fragment: '',
  _formatted: null,
  _fsPath: null
}

[dhruvmanila]

And, I think this is why Pyright raised "heap out of memory" error because it tried to index the entire home directory.

[MichaReiser]

I think we're able to parse it but . has no parent directory

[dhruvmanila]

I think we're able to parse it but . has no parent directory

I don't think so:

  24.044426375s ERROR     ruff:main notification{method="workspace/didChangeWorkspaceFolders"}: ruff_server::server::api: An error occurred while running workspace/didChangeWorkspaceFolders: Failed to convert workspace URL to file path: file://./

which happens at:

ruff/crates/ruff_server/src/session/index.rs

Lines 414 to 416 in 443bf38

	let workspace_path = workspace_url.to_file_path().map_err(|()| {
	anyhow!("Failed to convert workspace URL to file path: {workspace_url}")
	})?;

[dhruvmanila]

Oh so we can parse it but it's not being considered a valid file path (sorry!)

And, yes, you're correct about the parent directory part